python-ebml/data_elements.py at master · python-ffmpegio/python-ebml · GitHub

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#pylint: disable=too-many-public-methods,too-many-ancestors

#pylint: disable=logging-format-interpolation,too-many-lines

"""

Elements that exist as accessors for their data, using the Parsed property:

EBML, Segment, Seek, Info, TrackEntry, Video, Audio, AttachedFile, Tag, Targets,

SimpleTag.

"""

from collections import defaultdict

from os import SEEK_SET

from itertools import chain

from operator import attrgetter, itemgetter

from . import Inconsistent

from .utility import hex_bytes, encode_var_int, fmt_time

from .tags import MATROSKA_TAGS

from .element import ElementMaster, ElementPlaceholder, ElementVoid, \

STATE_UNLOADED, STATE_SUMMARY

from .parsed import Parsed, create_atomic

from .sortedlist import SortedList

__all__ = ['ElementEBML', 'ElementSegment', 'ElementSeek', 'ElementInfo',

'ElementTrackEntry', 'ElementVideo', 'ElementAudio',

'ElementAttachedFile', 'ElementTag', 'ElementTargets',

'ElementSimpleTag', 'ElementEditionEntry']

import logging #pylint: disable=wrong-import-order,wrong-import-position

LOG = logging.getLogger(__name__)

LOG.setLevel(logging.INFO)

# TODO: write EBMLReadVersion and DocTypeReadVersion correctly

class ElementEBML(ElementMaster):

"""Class to extract metadata from an EBML Element.

Attributes:

+ version: The value of the EBMLVersion element.

+ read_version: The value of the EBMLReadVersion element.

+ max_id_length: The value of the EBMLMaxIDLength element.

+ max_size_length: The value of the EBMLMaxSizeLength element.

+ doc_type: The value of the DocType element.

+ doc_type_version: The value of the DocTypeVersion element.

+ doc_type_read_version: The value of the DocTypeReadVersion element.

"""

version = Parsed('EBMLVersion', 'value', 'value', create_atomic())

read_version = Parsed('EBMLReadVersion', 'value', 'value', create_atomic())

max_id_length = Parsed('EBMLMaxIDLength', 'value', 'value', create_atomic())

max_size_length = Parsed('EBMLMaxSizeLength', 'value', 'value',

create_atomic())

doc_type = Parsed('DocType', 'value', 'value', create_atomic())

doc_type_version = Parsed('DocTypeVersion', 'value', 'value',

create_atomic())

doc_type_read_version = Parsed('DocTypeReadVersion', 'value', 'value',

create_atomic())

def __str__(self):

return "{}: V{}/{} ID:{} SZ:{} {!r} V{}/{}" \

.format(self.__class__.__name__,

self.version, self.read_version,

self.max_id_length, self.max_size_length,

self.doc_type, self.doc_type_version,

self.doc_type_read_version)

def check_read_handled(self):

"Check if we support reading the file."

return self.read_version <= 1 and self.max_id_length <= 4 and \

self.max_size_length <= 8 and \

self.doc_type.lower() == 'matroska' and \

self.doc_type_read_version <= 4

def check_write_handled(self):

"Check if we support writing the file."

return self.version <= 1 and self.max_id_length == 4 and \

self.max_size_length == 8 and \

self.doc_type.lower() == 'matroska' and \

self.doc_type_version <= 4

class ElementSegment(ElementMaster):

"""Class to extract metadata from a Segment.

This class takes advantage of SeekHead elements to extract the following

metadata from a Segment element.

Elements and element lists:

+ seek_heads: Iterator over SeekHead elements.

+ seek_entries: Iterator over Seek elements.

+ seek_entries_byid: Dict whose keys are EBML IDs and whose values are

SortedList's of relative positions where that child entry may be found.

+ tracks: Iterator over TrackEntry elements.

+ tracks_bytype: Dict whose keys are track type strings (as defined in the

TrackType Tag) and whose values are SortedList's of TrackEntry elements.

+ tracks_byuid: Dict whose keys are track UID ints and whose values are the

corresponding TrackEntry elements.

+ attachments: Iterator over AttachedFile elements.

+ attachments_byname: Dict of AttachedFile elements, stored by FileName.

+ attachments_byuid: Dict of AttachedFile elements, stored by FileUID.

+ editions: Iterator over EditionEntry elements from the Chapters element,

if any.

+ chapters: Iterator over ChapterAtom elements from the first EditionEntry

in the Chapters element, if any.

+ tags: Iterator over Tag elements, i.e. tag groups.

Extracted from Info elements:

+ uid: SegmentUID, a 128-bit bytes object; None if not defined.

+ timecode_scale: TimecodeScale, the timestap scale in nanoseconds

(unsigned integer).

+ duration: Segment duration in seconds (float); None if not defined.

+ title: Title, the Global title of the segment (string); None if not

defined.

+ muxing_app: MuxingApp (string); None if not defined.

+ writing_app: WritingApp (string); None if not defined.

Other:

+ clusters_pos: SortedList of pairs (start, end), where start is the

relative position of the beginning of a Clusters block and end is

(probably) where it ends. Set by read_summary().

"""

def __init__(self, header, name='Segment'):

super().__init__(header, name)

self.clusters_pos = SortedList(key=itemgetter(1))

self._placeholders_recursion = 0

self._replaced = {} # Elements replaced by placeholders

level_ones = {'SeekHead', 'Info', 'Tracks', 'Attachments', 'Chapters',

'Tags', 'Cluster', 'Cues'}

# Properties

@property

def seek_heads(self):

"Iterate over SeekHead elements."

yield from self.children_named('SeekHead')

@property

def seek_entries(self):

"Iterate over Seek elements."

for seek_head in self.seek_heads:

yield from seek_head.children_named('Seek')

@property

def seek_entries_byid(self):

"Get a dict whose keys are EBML IDs and whose values are positions."

ret = defaultdict(SortedList)

for seek in self.seek_entries:

ret[seek.seek_id].insert(seek.seek_pos)

return ret

@property

def seek_entries_byname(self):

"Get a dict mapping element names to positions."

ret = defaultdict(SortedList)

for seek in self.seek_entries:

ret[MATROSKA_TAGS[seek.seek_id].name].insert(seek.seek_pos)

return ret

@property

def tracks(self):

"Iterate over TrackEntry elements."

for tracks in self.children_named('Tracks'):

yield from tracks.children_named('TrackEntry')

@property

def tracks_bytype(self):

"Get a dict track_type -> list of Track entries."

ret = defaultdict(list)

for track in self.tracks:

ret[track.track_type].append(track)

return ret

@property

def tracks_byuid(self):

"Get a dict track_uid -> Track entry."

ret = {}

for track in self.tracks:

ret[track.track_uid] = track

return ret

@property

def attachments(self):

"Iterate over AttachedFile elements."

for attached_files in self.children_named('Attachments'):

yield from attached_files.children_named('AttachedFile')

@property

def tags(self):

"Iterate over Tag elements."

for tags in self.children_named('Tags'):

yield from tags.children_named('Tag')

@property

def attachments_byname(self):

"Get a dict of AttachedFile elements stored by FileName."

ret = {}

for attachment in self.attachments:

ret[attachment.file_name] = attachment

return ret

@property

def attachments_byuid(self):

"Get a dict of AttachedFile elements stored by FileUID."

ret = {}

for attachment in self.attachments:

ret[attachment.file_uid] = attachment

return ret

def duration_getter(self, child):

"Get child.duration, scaling to seconds."

return child.duration * self.timecode_scale / 1e9

def duration_setter(self, child, val):

"Set child.duration, scaling to seconds."

child.duration = val * 1e9 / self.timecode_scale

def delete_title(self, _):

"Delete the title from all Info children."

for child in self.children_named('Info'):

del child.title

# From Info elements

uid = Parsed('Info', 'segment_uid', 'segment_uid', skip=None)

timecode_scale = Parsed('Info', 'timecode_scale', 'timecode_scale')

duration = Parsed('Info', duration_getter, duration_setter, skip=None)

title = Parsed('Info', 'title', 'title', skip=None, deleter=delete_title)

muxing_app = Parsed('Info', 'muxing_app', 'muxing_app', skip=None)

writing_app = Parsed('Info', 'writing_app', 'writing_app', skip=None)

# From Chapters element

@property

def editions(self):

"Iterate over the children of the Chapters element, if any."

elt = self.child_named('Chapters')

if elt is None:

raise StopIteration

yield from elt.children_named('EditionEntry')

@property

def chapters(self):

"Iterate over the ChapterAtom children of the first EditionEntry."

edition = next(self.editions) # May raise StopIteration

yield from edition.chapters

# Manipulating children

def add_attachment(self, file_name, mime_type, description=None):

"""Create a new AttachedFile element if necessary.

Also create a new Attachments element if necessary. Return the new

ElementAttachedFile, or the old one if an attached file of that name

already existed.

"""

attachment = self.attachments_byname.get(file_name)

if attachment is not None:

attachment.file_mime_type = mime_type

if description is not None:

attachment.file_description = description

return attachment

attachments = self.child_named('Attachments')

if attachments is None:

attachments = ElementMaster.new('Attachments', self, 0)

attached_file = ElementAttachedFile.new('AttachedFile', attachments)

attached_file.file_name = file_name

attached_file.file_mime_type = mime_type

attached_file.file_data = b''

import uuid

attached_file.file_uid = uuid.uuid4().bytes_le[0:8]

if description is not None:

attached_file.file_description = description

return attached_file

def del_attachment(self, file_name):

"Delete an attached file if it exists."

attachment = self.attachments_byname.get(file_name)

if attachment is not None:

attachments = attachment.parent

attachments.remove_child(attachment)

if not len(list(attachments.children_named('AttachedFile'))):

# AttachedFile is a mandatory child

self.remove_child(attachments)

# Printing

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

ind_str = " " * (indent+4)

ret += ind_str + "Segment UID: {}\n".format(hex_bytes(self.uid))

ret += ind_str + "Title: {!r}\n".format(self.title)

ret += ind_str + "Duration: {:.2f} seconds\n".format(self.duration)

ret += ind_str + "Time scale: {} nanoseconds\n" \

.format(self.timecode_scale)

ret += ind_str + "Muxing app: {!r}\n".format(self.muxing_app)

ret += ind_str + "Writing app: {!r}\n".format(self.writing_app)

ret += ind_str + "Seek entries:\n"

for ebml_id, positions in self.seek_entries_byid.items():

if ebml_id in MATROSKA_TAGS:

ebml_name = MATROSKA_TAGS[ebml_id].name

else:

ebml_name = "[{}]".format(

hex_bytes(encode_var_int(ebml_id, range(1, 5))))

ret += ind_str + " {:<13} {}\n" \

.format(ebml_name + ":",

", ".join(str(pos) for pos in positions))

ret += ind_str + "Attachments:\n"

for attachment in self.attachments:

ret += attachment.summary(indent+8) + "\n"

ret += ind_str + "Tracks:\n"

for track in self.tracks:

ret += track.summary(indent+8) + "\n"

ret += ind_str + "Tags:\n"

for tags in self.tags:

ret += tags.summary(indent+8) + "\n"

ret += ind_str + "Chapters:\n"

for chapter in self.chapters:

ret += chapter.summary(indent+8) + "\n"

return ret[:-1]

# Reading and writing

def _read_until_clusters(self, stream, cur_pos):

"Read elements from cur_pos until we hit Clusters or EOS."

while cur_pos < self.size:

tag = self.peek_element(stream)

if tag is None:

raise EOFError("Unexpected end of stream at {}".format(cur_pos))

if tag.name == 'Cluster': # At clusters

return cur_pos

child = self.read_element(stream, cur_pos,

summary=True, seekfirst=False)

cur_pos += child.total_size

return None

def read_summary(self, stream, seekfirst=True):

"""Partially read this element.

This method tries to find all non-Cluster elements. It does this using

Seek entries and reading after every known element until it hits a

Cluster.

"""

if seekfirst:

stream.seek(self.pos_data_absolute, SEEK_SET)

# Read everything at the beginning

cur_pos = self._read_until_clusters(stream, 0)

if cur_pos is None or cur_pos == 0:

return # Clusters started immediately or no clusters?

clusters_pos = [cur_pos]

# Read after other elements

while True:

# Figure out if there might be something left to read

cur_pos = None

for child in self:

end = child.pos_end_relative

if end in clusters_pos:

continue

try:

self.find(end)

except ValueError:

cur_pos = end

break

if cur_pos is None or cur_pos >= self.size:

break

stream.seek(self.pos_data_absolute + cur_pos, SEEK_SET)

cur_pos = self._read_until_clusters(stream, cur_pos)

if cur_pos is not None:

clusters_pos.append(cur_pos)

# Save cluster positions

self.clusters_pos = SortedList(key=itemgetter(1))

for cluster_start in clusters_pos:

if cluster_start == self.size:

continue

try:

child = self.find_gt(cluster_start)

except ValueError:

self.clusters_pos.insert((cluster_start, self.size))

else:

self.clusters_pos.insert((cluster_start, child.pos_relative))

stream.seek(self.pos_end_absolute, SEEK_SET)

self.read_state = STATE_SUMMARY

def read_data(self, stream, seekfirst=True):

super().read_data(stream, seekfirst)

self.clusters_pos = SortedList(key=itemgetter(1))

def parse_SeekHead(self, child, stream): #pylint: disable=invalid-name

"Parse SeekHead element and recursively read elements."

LOG.debug("Segment: parsed {}".format(child))

recursed = False

for seek_entry in child.children_named('Seek'):

try:

self.find(seek_entry.seek_pos)

except ValueError:

# Recurse if this is the first time we've seen this seek entry

LOG.debug("Segment: adding seek entry {}".format(seek_entry))

if seek_entry.seek_id_name != 'Cluster' and stream:

# This recursively reads any elements this seek entry

# points to that haven't been read already.

self.read_element(stream, seek_entry.seek_pos,

summary=True, seekfirst=True)

recursed = True

if recursed:

stream.seek(child.pos_end_absolute, SEEK_SET)

def _add_placeholders(self):

"""Add LibInternal elements over detected Cluster blocks.

Also replace loaded Cluster and Cues blocks with placeholders if in

summary mode since they're MasterDefer elements.

"""

self._placeholders_recursion += 1

if self._placeholders_recursion > 1:

return

for start, end in self.clusters_pos:

ElementPlaceholder.of_size('LibInternal', end - start, self, start)

self.clusters_pos = SortedList(key=itemgetter(1))

if self.read_state == STATE_SUMMARY:

for elt in chain(self.children_named('Cluster'),

self.children_named('Cues')):

temp = ElementPlaceholder.of_size(

'LibInternal2', elt.total_size, self, elt.pos_relative)

self._replaced[elt] = temp

self.remove(elt)

def _remove_placeholders(self):

"Remove all LibInternal children."

self._placeholders_recursion -= 1

if self._placeholders_recursion > 0:

return

for elt, temp in self._replaced.items():

elt.pos_relative = temp.pos_relative

self.insert(elt)

self.remove(temp)

self._replaced = {}

for temp in list(self.children_named('LibInternal')):

self.clusters_pos.insert((temp.pos_relative, temp.pos_end_relative))

self.remove_child(temp)

def _placeholders(self):

"Return a context manager to handle placeholders."

class CM:

"Context manager to handle placeholders."

#pylint: disable=too-few-public-methods,protected-access

def __init__(self, seg):

self.seg = seg

def __enter__(self):

self.seg._add_placeholders()

def __exit__(self, exc_type, exc_value, traceback):

self.seg._remove_placeholders()

return CM(self)

def normalize(self):

"""Rearrange level-1 elements into a reasonable configuration.

This method does several things:

1. It expands the header to its maximum size.

2. It reconstructs the SeekHead element, consolidating existing ones

and placing it at the beginning of the Segment.

3. It recursively rearranges all other elements to put everything in a

consistent state.

4. It grows this element if necessary. It will not shrink.

One thing this method will never do is move (from its absolute position)

or otherwise modify any Cluster or Cues element.

Raises:

+ Inconsistent, if there is not enough space before the Clusters for

the SeekHead, or if anything else bizarre happens. In case of

non-local exit the Element itself will be in an inconsistent state

and should be deleted.

"""

#pylint: disable=too-many-branches

# For reference, the level-1 elements are (m=multiple):

# SeekHead(m), Info(m), Tracks(m), Attachments, Chapters, Tags,

# Cluster(m), Cues

if self.read_state == STATE_UNLOADED:

raise Inconsistent("Tried to normalize() unloaded Segment")

to_index = self.level_ones - {'SeekHead', 'Cluster'}

to_rearrange = self.level_ones - {'Cluster', 'Cues', 'SeekHead'}

# Delete Voids and SeekHeads

self.remove_children_named('Void')

self.remove_children_named('SeekHead')

# Make new SeekHead. The positions may get modified, but we use the

# maximum amount of space to store them so the total size will be

# unchanged.

seek_head = ElementMaster.new('SeekHead', self, 0)

for child in self:

if child.name in to_index:

seek_head.add_child(ElementSeek.new_index(child))

# Add placeholders *after* making the new SeekHead

self._add_placeholders()

# Expand header to maximum size

self.expand_header(self.header.numbytes_size_max)

# Put children in a consistent state.

for child in self:

if child.name in to_rearrange:

child.rearrange_if_necessary(prefer_grow=False,

allow_shrink=True)

seek_head.rearrange_resize(prefer_grow=False, allow_shrink=True)

self.move_child(seek_head, 0)

# Collect and replace overlapping elements

to_replace = set(self.get_overlapping(fixed=(

'SeekHead', 'Cluster', 'Cues', 'LibInternal', 'LibInternal2')))

to_replace_byname = defaultdict(

lambda: SortedList(key=attrgetter('total_size')))

for elt in to_replace:

to_replace_byname[elt.name].insert(elt)

clusters_start \

= min([elt.pos_relative \

for elt in chain(self.children_named('Cluster'),

self.children_named('LibInternal'))]

+ [self.size])

# Prefer to put these element types at the beginning:

for elt_name in ('Info', 'Tracks'):

for elt in reversed(to_replace_byname[elt_name]):

try:

self.place_child(elt, 0, clusters_start)

except Inconsistent:

self.place_child(elt)

to_replace.remove(elt)

# Place the rest where they fit best

to_replace = list(to_replace)

to_replace.sort(key=attrgetter('total_size'))

for elt in reversed(to_replace):

self.place_child(elt)

# Cleanup

if self.end_last_child == self.size - 1:

self.resize(self.size + 1)

elif self.end_last_child > self.size:

self.resize(self.end_last_child)

self._fill_gaps()

if self.size > self.end_last_child:

ElementVoid.of_size(self.size - self.end_last_child,

self, self.end_last_child)

self._remove_placeholders()

# Finalize seek entries

for seek in seek_head:

seek.seek_pos = seek.child.pos_relative

def check_consecutivity(self, child_consistency=False):

with self._placeholders():

super().check_consecutivity(child_consistency)

def write(self, stream, seekfirst=True):

with self._placeholders():

super().write(stream, seekfirst)

# Logging

def parse_Info(self, child, stream):

#pylint: disable=invalid-name,unused-argument,no-self-use

"Log Info parsing."

LOG.debug("Segment: parsed {}".format(child))

def parse_Tracks(self, child, stream):

#pylint: disable=invalid-name,unused-argument,no-self-use

"Log Tracks parsing."

LOG.debug("Segment: parsed {}".format(child))

def parse_Cues(self, child, stream):

#pylint: disable=invalid-name,unused-argument,no-self-use

"Log Cues parsing."

LOG.debug("Segment: parsed {}".format(child))

def parse_Attachments(self, child, stream):

#pylint: disable=invalid-name,unused-argument,no-self-use

"Log Attachments parsing."

LOG.debug("Segment: parsed {}".format(child))

def parse_Chapters(self, child, stream):

#pylint: disable=invalid-name,unused-argument,no-self-use

"Log Chapters parsing."

LOG.debug("Segment: parsed {}".format(child))

def parse_Tags(self, child, stream):

#pylint: disable=invalid-name,unused-argument,no-self-use

"Log Tags parsing."

LOG.debug("Segment: parsed {}".format(child))

class ElementSeek(ElementMaster):

"""Class for a Seek element.

Attributes:

+ seek_id: The value of the SeekID child, an EBML ID.

+ seek_id_name: The tag name of ID seek_id.

+ seek_id_raw: The encoded EBML ID.

+ seek_pos: The value of the SeekPosition child; this is the pos_relative

of the direct child of the Segment element.

Two instances of this class compare equal if they have the same seek_id and

seek_pos.

"""

@classmethod

def new_index(cls, elt):

"""Create a new SeekHead indexing elt."""

ret = cls.new('Seek')

ret.seek_id = elt.ebml_id

ret.seek_pos = max([0, elt.pos_relative])

ret.child = elt # for internal use

return ret

def __init__(self, header, name='SeekHead'):

super().__init__(header, name)

self.child = None

seek_id = Parsed('SeekID', 'value', 'value', create_atomic())

seek_id_name = Parsed('SeekID', 'string_name', default="NOT DEFINED")

seek_id_raw = Parsed('SeekID', 'raw')

seek_pos = Parsed('SeekPosition', 'value', 'value', create_atomic())

def __str__(self):

return "{}: [{}] ({}) at {}".format(self.__class__.__name__,

hex_bytes(self.seek_id_raw),

self.seek_id_name, self.seek_pos)

class ElementInfo(ElementMaster):

"""Class for an Info element.

Attributes:

+ segment_uid: The value of the SegmentUID element, if any; None otherwise.

+ timecode_scale: The value of the TimecodeScale element, if any; 1000000

otherwise (the Matroska default).

+ duration: The value of the Duration element, if any; None otherwise.

+ title: The value of the Title element, if any; None otherwise.

+ muxing_app: The value of the MuxingApp element, if any; None otherwise.

+ writing_app: The value of the WritingApp element, if any; None otherwise.

"""

segment_uid = Parsed('SegmentUID', 'value', 'value', create_atomic())

timecode_scale = Parsed('TimecodeScale', 'value', 'value', create_atomic())

duration = Parsed('Duration', 'value', 'value', create_atomic())

title = Parsed('Title', 'value', 'value', create_atomic())

muxing_app = Parsed('MuxingApp', 'value', 'value', create_atomic())

writing_app = Parsed('WritingApp', 'value', 'value', create_atomic())

class ElementTrackEntry(ElementMaster):

"""Class for a TrackEntry element.

Extract track metadata from a TrackEntry element.

Attributes:

+ track_type: The value of the TrackType element, a string representing the

enum value.

+ track_name: The value of the Name element, if any; None otherwise

(string).

+ track_language: The value of the Language element, if any; "eng"

otherwise (the Matroska default).

+ codec_id: The value of the CodecID element (string).

+ codec_name: The value of the CodecName element, if any; None otherwise

(string).

+ track_number: The value of the TrackNumber element (int).

+ track_uid: The value of the TrackUID element (int).

+ flag_enabled: The value of the FlagEnabled element (bool).

+ flag_default: The value of the FlagDefault element (bool).

+ flag_forced: The value of the FlagForced element (bool).

+ flag_lacing: The value of the FlagLacing element (bool).

+ video: ElementVideo instance, for tracks of type 'video'.

+ audio: ElementAudio instance, for tracks of type 'audio'.

+ track_index: The index of this TrackEntry in the list of tracks in its

segment.

"""

track_type = Parsed('TrackType', 'string_val', 'value',

create_atomic(), default='UNKNOWN')

track_name = Parsed('Name', 'value', 'value', create_atomic())

track_language = Parsed('Language', 'value', 'value', create_atomic())

codec_id = Parsed('CodecID', 'value', 'value', create_atomic())

codec_name = Parsed('CodecName', 'value', 'value', create_atomic())

track_number = Parsed('TrackNumber', 'value', 'value', create_atomic())

track_uid = Parsed('TrackUID', 'value', 'value', create_atomic())

flag_enabled = Parsed('FlagEnabled', 'value', 'value', create_atomic())

flag_default = Parsed('FlagDefault', 'value', 'value', create_atomic())

flag_forced = Parsed('FlagForced', 'value', 'value', create_atomic())

flag_lacing = Parsed('FlagLacing', 'value', 'value', create_atomic())

video = Parsed('Video', '')

audio = Parsed('Audio', '')

@property

def track_index(self):

"Return the index of this TrackEntry in its containing segment."

segment = self.parent.parent

if not isinstance(segment, ElementSegment):

raise ValueError("Track is not contained in a segment")

for idx, other in enumerate(segment.tracks):

if other is self:

return idx

def __str__(self):

ret = "{}: {} lang={} codec={} num={} uid={}" \

.format(self.__class__.__name__, self.track_type,

self.track_language, self.codec_id, self.track_number,

self.track_uid)

if self.track_name:

ret += ": " + repr(self.track_name)

return ret

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

ind_str = " " * (indent+4)

if self.codec_name:

ret += ind_str + "Codec: {!r}\n".format(self.codec_name)

flags = ["enabled", "default", "forced", "lacing"]

flags_vals = []

for flag in flags:

if getattr(self, "flag_" + flag):

flags_vals.append(flag)

else:

flags_vals.append("!" + flag)

ret += ind_str + "Flags: {}\n".format(" ".join(flags_vals))

if self.video:

ret += self.video.summary(indent+4) + "\n"

if self.audio:

ret += self.audio.summary(indent+4) + "\n"

return ret[:-1]

class ElementVideo(ElementMaster):

"""Class for a Video element.

Extract track metadata from a Video element.

Attributes:

+ pixel_dims: Pair (width, height) of int's consisting of the values of the

PixelWidth and PixelHeight elements.

+ display_dims: Pair (width, height) of int's consisting of the values of

the DisplayWidth and DisplayHeight elements. Defaults to pixel_dims.

+ display_unit: The value of the DisplayUnit element, if any; 'pixels'

otherwise. This is the string representing the enum value.

+ pixel_crop: List (top, bottom, left, right) of int's consisting of the

values of the PixelCrop* elements. They default to 0.

+ stereo_mode: The value of the StereoMode element, if any; 'mono'

otherwise. This is the string representing the enum value.

+ aspect_ratio_type: The value of the AspectRatioType element, if any;

'free resizing' otherwise. This is the string representing the enum

value.

+ colour_space: The value of the ColourSpace element, if any; None

otherwise (bytes).

+ alpha_mode: value of the AlphaMode element, if any; 0 otherwise (int).

+ flag_interlaced: The value of the FlagInterlaced element (bool).

"""

#pylint: disable=too-many-instance-attributes

pixel_width = Parsed('PixelWidth', 'value', 'value', create_atomic())

pixel_height = Parsed('PixelHeight', 'value', 'value', create_atomic())

display_width = Parsed('DisplayWidth', 'value', 'value', create_atomic(),

default=attrgetter('pixel_width'))

display_height = Parsed('DisplayHeight', 'value', 'value', create_atomic(),

default=attrgetter('pixel_height'))

pixel_crop_top = Parsed('PixelCropTop', 'value', 'value', create_atomic())

pixel_crop_bottom = Parsed('PixelCropBottom', 'value', 'value',

create_atomic())

pixel_crop_left = Parsed('PixelCropLeft', 'value', 'value', create_atomic())

pixel_crop_right = Parsed('PixelCropRight', 'value', 'value',

create_atomic())

display_unit = Parsed('DisplayUnit', 'string_val', 'value',

create_atomic(), default='pixels')

stereo_mode = Parsed('StereoMode', 'string_val', 'value',

create_atomic(), default='mono')

aspect_ratio_type \

= Parsed('AspectRatioType', 'string_val', 'value',

create_atomic(), default='free resizing')

colour_space = Parsed('ColourSpace', 'value', 'value', create_atomic())

alpha_mode = Parsed('AlphaMode', 'value', 'value', create_atomic())

flag_interlaced = Parsed('FlagInterlaced', 'value', 'value',

create_atomic())

@property

def pixel_dims(self):

"Get pixel dims as (width, height)."

return (self.pixel_width, self.pixel_height)

@pixel_dims.setter

def pixel_dims(self, val):

"Set pixel_dims to val=(width, height)."

self.pixel_width, self.pixel_height = val

@property

def display_dims(self):

"Get display dims as (width, height), defaulting to pixel_dims."

return (self.display_width, self.display_height)

@display_dims.setter

def display_dims(self, val):

"Set display_dims to val=(width, height)."

self.display_width, self.display_height = val

@property

def pixel_crop(self):

"Get pixel crop as (top, bottom, left, right)."

return (self.pixel_crop_top, self.pixel_crop_bottom,

self.pixel_crop_left, self.pixel_crop_right)

@pixel_crop.setter

def pixel_crop(self, val):

"Set pixel crop to val=(top, bottom, left, right)."

self.pixel_crop_top, self.pixel_crop_bottom, \

self.pixel_crop_left, self.pixel_crop_right = val

def __str__(self):

return "{0}: dims={p[0]}x{p[1]}, display={d[0]}x{d[1]}, aspect={1!r}" \

.format(self.__class__.__name__, self.aspect_ratio_type,

p=self.pixel_dims, d=self.display_dims)

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

ind_str = " " * (indent+4)

ret += ind_str + "Stereo: {}\n".format(self.stereo_mode)

ret += ind_str + "Interlaced: {}\n".format(bool(self.flag_interlaced))

if self.pixel_crop != (0, 0, 0, 0):

ret += ind_str + "Crop: {}:{}:{}:{}\n" \

.format(*self.pixel_crop)

return ret[:-1]

class ElementAudio(ElementMaster):

"""Class for an Audio element.

Extract track metadata from an Audio element.

Attributes:

+ channels: The value of the Channels element (int).

+ bit_depth: The value of the BitDepth element, if any; None otherwise

(int).

+ sampling_frequency: The value of the SamplingFrequency element, in Hz

(float).

+ output_sampling_frequency: The value of the OutputSamplingFrequency

element, if any, in Hz (float). Defaults to sampling_frequency.

"""

channels = Parsed('Channels', 'value', 'value', create_atomic())

bit_depth = Parsed('BitDepth', 'value', 'value', create_atomic())

sampling_frequency = Parsed('SamplingFrequency', 'value', 'value',

create_atomic())

output_sampling_frequency \

= Parsed('OutputSamplingFrequency', 'value', 'value', create_atomic(),

default=attrgetter('sampling_frequency'))

def __str__(self):

return "{}: channels={} sampling={}k" \

.format(self.__class__.__name__, self.channels,

int(self.sampling_frequency/1000))

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

ind_str = " " * (indent+4)

if self.bit_depth:

ret += ind_str + "Bit depth: {}\n".format(self.bit_depth)

if self.sampling_frequency != self.output_sampling_frequency:

ret += ind_str + "Output freq: {}\n" \

.format(int(self.output_sampling_frequency/1000))

return ret[:-1]

class ElementAttachedFile(ElementMaster):

"""Class for an AttachedFile element.

Attributes:

+ file_name: The value of the FileName element, a string.

+ file_uid: The value of the FileUID element, a bytes object.

+ file_description: The value of the FileDescription element, if any; None

otherwise.

+ file_mime_type: The value of the FileMimeType element, a string.

+ file_data: The FileData element's data. This can be large.

+ file_size: The size of self.file_data.

"""

file_name = Parsed('FileName', 'value', 'value', create_atomic())

file_uid = Parsed('FileUID', 'value', 'value', create_atomic())

file_description = Parsed('FileDescription', 'value', 'value',

create_atomic())

file_mime_type = Parsed('FileMimeType', 'value', 'value', create_atomic())

file_data = Parsed('FileData', 'value', 'value', create_atomic())

file_size = Parsed('FileData', 'size', default=0)

def __str__(self):

ret = "{}: {!r} ({}), {} bytes" \

.format(self.__class__.__name__, self.file_name,

self.file_mime_type, self.file_size)

if self.file_description:

ret += ": " + repr(self.file_description)

return ret

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

ind_str = " " * (indent+4)

ret += ind_str + "UID: {}\n".format(hex_bytes(self.file_uid))

return ret[:-1]

class ElementTag(ElementMaster):

"""Class for a Tag element, i.e. a tag group.

Attributes:

+ targets: The Targets element.

+ target_type_value: The TargetTypeValue child of the Targets element.

+ target_type: The TargetType child of the Targets element.

+ simple_tags: Iterator over SimpleTag children.

"""

@classmethod

def new_with_value(cls, target_type_value, target_type,

parent=None, pos_relative=None):

"Create a new tag group."

ret = cls.new('Tag', parent, pos_relative)

targets = ElementTargets.new('Targets', ret)

targets.target_type_value = target_type_value

targets.target_type = target_type

return ret

@property

def simple_tags(self):

"Iterate over SimpleTag elements."

yield from self.children_named('SimpleTag')

targets = Parsed('Targets', '')

target_type_value = Parsed('Targets', 'target_type_value',

'target_type_value')

target_type = Parsed('Targets', 'target_type', 'target_type')

def __str__(self):

return "{}: {} ({}), {} tags" \

.format(self.__class__.__name__, self.target_type,

self.target_type_value, len(list(self.simple_tags)))

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

for tag in self.simple_tags:

ret += tag.summary(indent+4) + "\n"

return ret[:-1]

class ElementTargets(ElementMaster):

"""Class for a Targets element.

Attributes:

+ target_type_value: The value of the TargetTypeValue element.

+ target_type: The value of the TargetType element.

"""

target_type_value = Parsed('TargetTypeValue', 'value', 'value',

create_atomic(), default=50)

target_type = Parsed('TargetType', 'value', 'value', create_atomic())

class ElementSimpleTag(ElementMaster):

"""Class for a SimpleTag element.

Attributes:

+ tag_name: The value of the TagName element.

+ language: The value of the TagLanguage element.

+ default: The value of the TagDefault element.

+ string_val: The value of the TagString element.

+ binary_val: The value of the TagBinary element.

+ sub_tags: Iterate over SimpleTag children.

"""

default_lang = 'eng'

@classmethod

def new_with_value(cls, tag_name, string_val,

parent=None, pos_relative=None, *, lang=None):

"Create a new SimpleTag with a name and a value."

ret = cls.new('SimpleTag', parent, pos_relative)

ret.tag_name = tag_name

if lang is None:

ret.language = cls.default_lang

else:

ret.language = lang

ret.default = True

ret.string_val = string_val

return ret

@property

def sub_tags(self):

"Iterate over SimpleTag elements."

yield from self.children_named('SimpleTag')

tag_name = Parsed('TagName', 'value', 'value', create_atomic())

language = Parsed('TagLanguage', 'value', 'value', create_atomic(),

default='und')

default = Parsed('TagDefault', 'value', 'value', create_atomic(),

default=True)

string_val = Parsed('TagString', 'value', 'value', create_atomic())

binary_val = Parsed('TagBinary', 'value', 'value', create_atomic())

def __str__(self):

return "{} lang={} def={!r}: {!r} => {!r}" \

.format(self.__class__.__name__, self.language,

bool(self.default), self.tag_name, self.string_val)

def summary(self, indent=0):

ret = super().summary(indent) + "\n"

for tag in self.sub_tags:

ret += tag.summary(indent+4) + "\n"

return ret[:-1]

class ElementChapterAtom(ElementMaster):

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